Charlie came from a poor village. His parents had 1 money to send him to school when he was young. The boy was very2 . Mr. King lived next to him. He knew it and lent some 3 to him. So the boy could go to school. He studied hard and 4all his lessons. When he finished middle school, Mr King introduced him to his friend in the town,  5 he began to work.

    Once Mr. King was hurt 6  in an accident. He was dying and he asked Charlie to take care of his 7, Sharon. The young man agreed and several years later he married the girl. He loved her very much and tried his best to make8  happy. He often bought delicious food for her. He was good at cooking and he cooked 9 for her. So she became very fat. And one day she found there was something wrong with her heart and she had to go to 10 at once. The doctors looked her over and told her 11 eat meat, sugar, chocolate and things like these. She was afraid 12 the doctor's words , so she wrote all the names of the food on the paper. When she got home, she put the paper on the table and 13. When she came back home that afternoon, she found many kinds of 14 : meat, sugar and chocolate in the kitchen. Charlie was busy 15 there. When he saw her, he said happily, "I bought all the food you like, dear!"

过氧化钠（Na₂O₂）是一种淡黄色固体．某次科技活动中，某化学兴趣小组的同学将包有过氧化钠固体的棉花放入图2烧杯中，缓慢倒入二氧化碳后发现位于下面的蜡烛先熄灭，上面的蜡烛后熄灭，同时也惊奇地发现棉花燃烧起来．

（1）实验过程中蜡烛先后熄灭的现象说明了二氧化碳的一些化学性质．

（2）棉花为什么会燃烧呢？同学们联想起物质燃烧的相关知识，推理出棉花要燃烧，除了满足“棉花是可燃物”这一条件，还另需满足的条件是：____ ．

提出问题：在实验中是如何给棉花燃烧提供条件的呢？

查阅资料：在常温下过氧化钠和二氧化碳能发生化学反应．

设计实验：经过讨论后，同学们设计了如下图的实验进行探究．

实验步骤：（1）按图1装配好装置，并检查其气密性；（2）把相关的试剂放入对应的仪器内；（3）推动注射器的活塞，把稀盐酸注入锥形瓶内，并固定活塞的位置；（4）一段时间后，在a处放置一根带火星的木条，观察现象．

实验现象：（1）干燥管中没有出现蓝色；（2）带火星的木条复燃；（3）饱和石灰水变浑浊．

实验分析：

（1）D装置的烧杯内变浑浊的原因是____ ；

（2）B装置中浓硫酸吸水干燥的作用，C装置的作用是____．

实验结论：

（1）“小木条复燃”说明过氧化钠和二氧化碳反应产生了____；

（2）“饱和的石灰水变浑浊”说明反应____ （填“吸收”或“放出”）热量，也使棉花满足了燃烧的条件．

— I'm feeling better.